{"cve":"CVE-2026-43365","nvd":{"published":"2026-05-08T15:16:47.490","modified":"2026-10-19T20:18:15.060","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: fix undersized l_iclog_roundoff values\n\nIf the superblock doesn't list a log stripe unit, we set the incore log\nroundoff value to 512.  This leads to corrupt logs and unmountable\nfilesystems in generic/617 on a disk with 4k physical sectors...\n\nXFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c\nXFS (sda1): Torn write (CRC failure) detected at log block 0x318e. Truncating head block from 0x3197.\nXFS (sda1): failed to locate log tail\nXFS (sda1): log mount/recovery failed: error -74\nXFS (sda1): log mount failed\nXFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c\nXFS (sda1): Ending clean mount\n\n...on the current xfsprogs for-next which has a broken mkfs.  xfs_info\nshows this...\n\nmeta-data=/dev/sda1              isize=512    agcount=4, agsize=644992 blks\n         =                       sectsz=4096  attr=2, projid32bit=1\n         =                       crc=1        finobt=1, sparse=1, rmapbt=1\n         =                       reflink=1    bigtime=1 inobtcount=1 nrext64=1\n         =                       exchange=1   metadir=1\ndata     =                       bsize=4096   blocks=2579968, imaxpct=25\n         =                       sunit=0      swidth=0 blks\nnaming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=1\nlog      =internal log           bsize=4096   blocks=16384, version=2\n         =                       sectsz=4096  sunit=0 blks, lazy-count=1\nrealtime =none                   extsz=4096   blocks=0, rtextents=0\n         =                       rgcount=0    rgsize=268435456 extents\n         =                       zoned=0      start=0 reserved=0\n\n...observe that the log section has sectsz=4096 sunit=0, which means\nthat the roundoff factor is 512, not 4096 as you'd expect.  We should\nfix mkfs not to generate broken filesystems, but anyone can fuzz the\nondisk superblock so we should be more cautious.  I think the inadequate\nlogic predates commit a6a65fef5ef8d0, but that's clearly going to\nrequire a different backport.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","score":8.2},"cwes":["CWE-20"],"references":["https://git.kernel.org/stable/c/2ecda4b83749c1fef0c9dea4fd5e8b513aba3e40","https://git.kernel.org/stable/c/41e91dff2d3974730b5ee50daa8e27ec254cbf91","https://git.kernel.org/stable/c/446a1f5bb64ba38adb93cb043ff0f7b85e8937ca","https://git.kernel.org/stable/c/52a8a1ba883defbfe3200baa22cf4cd21985d51a","https://git.kernel.org/stable/c/5afae524f83d6a18517298491a5624cb0eae5029"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-43365","score":0.00506,"percentile":0.42922,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}